Hi Ace
You have 3 options on what to do here and this depends on how you are going to remove the original paints.. ie the Silver and the Red.
First option is to use Tamiya's 40mm masking tape which is pretty transparent and ideal for following lines that you can see through it..
Place the tape over the areas that you want to copy and simply follow the devide between the colours using a good H2 pencil.. remove the tape and then using a fine scalpel cut out the desired piece and place it on a flat surface later for removal and remasking.. remember to number it or mark it left/right.
Option 2 is to put the masking tape over the area as above but with a fine scalpel, follow the line making sure you do not cut too deep and the remove the piece that will not be needed leaving the tape covering and protecting the area not beeing sprayed..
Option 3 and the one i use is to run a scalpel along all the lines deviding the red/silver as to give a "guide line" to where the edges are.. you might have to press a bit harder to get a good line but not too hard as you dont want to break/snap the tip of the blade..
Once your happy that you have the lines then you can remove all the paint back to the ABS Plastic with either 4000 grit Micro mesh or another option which does work and I have done with no problems is to use break Fluid warmed up in a bowl... This left over an hour or so will eat away the paint but not harm the ABS.. It will turn it a milky colour but thats about it... The only problem is it's messy and requires more time...
The pictures below show the brake fluid method and the masking method.. you can see where the silver has had an effect on the ABS once removed but this id the "milky" look it gives and can assure that all the paint is gone.. The Side Cowel pod shows the tape and how seethrough it is..and the final one is of the parts reprayed ready for a gloss coat and then the chrome at a later time..
Warthog attached the following image(s):
US
